Automatic transmission



April 16, 1935. J. J. DRABlN 1,998,274

AUTOMATIC TRANSMISSION Filed July 9, 1954 2 Sheets-Sheet 2 JOHN ef RAa/N lNvNToR BY Qn@ ATTORNEY Patented Apr. 16, igt/ I y l t y "UNITED STATES PATENT OFFICE 1,99s,z 14 AUTOMATIC TRANSMISSION John J. Drabin, New York, N. Y.

Application July 9, 1934, Serial No. 734,246

'z claims. (ci. 'i4-336.5)

My invention relates to an automatic transmiscompanying specification and drawings in sion and has particular reference to a transmiswhichsion for an automobile or a similar automotive Fig. 1 is a partial elevation of an automobile vehicle. power plant withmy automatic transmission, 5 This is a continuation in part of my applica- Fig. 2 is a top plan view of the same partly in 5 tion Serial No. 688,339, filed Sept. 6, 1933. section, Fig. 3 .is an end view of the same, Fig. 4

In ordinary automobile transmissions the gear is a detail view of the governor, Fig. 5 is a detail shift is accomplished manually. the operation review of the removable gear shift handle, Fig. 6 `quiring a certain amount of skill on the part of is a detail view of the device for locking the l0 the driver. The gear shift is made easier by transmission when the reverse gear is in mesh, 10

certain improvements, such as an automatic ar- Fig. 'I is a diagrammatic view of the gear shift rangement for synchronizing the respective gears ing mechanism in the positon when low gear is before bringing them into mesh, also by a more in mesh. Fig. 8 is a similar view showing the or less automatic operation of the'engine clutch. gears in neutral between low and second gears,

It is desirable, however, to have a fully auto- Fig. 9 is a view showing the second gear in mesh'. 15

matic transmission, in which all thegear shifts, Fig. 10 is a view showing next transitory neutral with the exception of the reverse, are accomposition, Fig. 11 is a view with the gears in high plished automatically, without any attention from gear, Fig. 12 is a similar view of the next neutral the driver, being controlled by the movement of position. Fig. 13 iS a detail View 0f .the Valve 001.1- the' vehicle itself. trol of the gear shifting cylinder, Fig. 14 is an 20 The object of my invention is to provide such end view of the cam shaft, Fig. l5 is a partial an automatic transmission. For this purpose I side view of the cam shaft, and Fig. 16 is a. detail provide a vacuum cylinder connected through a view of the cam mechanism.

valve with the intake manifold of the automobile I use for my transmission a standard gear engine, and I connect this cylinder with the gear .housing or box I with ordinary selective sliding 25 shifting rods in the transmission. I provide a transmission'gears 2. Gear shifting rods 3 and mechanism for selectively connecting the cylin- 4 are provided, the rod 3 being for the reverse der with one or the other of the shifting rods; and the first speeds, and the rod 4 for the second for controlling the operation4 of these selective and third speeds. The rods are provided with connections I provide a centrifugal governor conslots 5 for the manual gear shifting lever 6 rota- 30 nected with the driven shaft of the transmission. tively supported in a bracket I and held in a I also provide operative connections between the middle or inoperative position by springs 8'. The governor and the valve of thev cylinder in order to handle 8 is usually 'removed' and the bracket covoperate the properr gear shifts when correspondered with a lid 9.' The reverse gear is shifted ing predetermined speeds of the driven shaft are manually by a lever IIv engaging a slot Il). A rod 35 reached. y I2 connects the lever Il with a crank I3 in which In view of the fact lthat it is desirable tor'aise slides a rod 35 with a bushing I3 and a handle the limits of the speed when more. engine power I4 slidably fitted in a dashboard I5. A springz is used, I provide connections between the ac'- latch I5' engages slots 3', 4 and 5 for the first 40 celerator pedal and the governor whereby the speed`neutral and reverse. 40 governor springs can be tightened when the ac- The.y rods 3 and 4 have pins I6 passing through celerator pedal is depressed. slots I1 and connected with the ends of arms I8 For the most satisfactory operation of my pivotally supported on pins, I9 at the sides of theI transmission it is desirable to have a servo motor box I. The lower ends of the arms are pivotally -iffor operating the yengine clutch. I prefer toconnected with links 20, the other ends of which use forA this purpose also a vacuum cylinder conare pivotedl to selector bars 2l and 22. These neet/ed with the intake manifold of the engine; bars are pivotally joined together at the middle The 'controlling valve of this clutch cylinder I point 23 which is also pivoted to the end of a slidconnect with the governor in such manner that ing rod 24. The other end of the rod 24 isatthe clutch is automatically disconnected every vtached to a piston 25 sliding in a cylinder 25. 50 time when gears are shifted. The-.ends of the cylinder are connected by a pipe 'Iprovide means in my system to revert to the 28 with a four-way valve 29. The third outlet of manual gear shifting if necessary, in which casethe valve is connected'with the outside air through the automatic devices become disconnected. a filter box 30 lled with metal shavings or simi- My invention is more fullydescribed in the aclar air filtering material. 55

and 42" in the selector bars 2| and 22.

'The fourth outlet is connected by a pipe 3| with the intake manifold 32 of the engine 33. A valve 34 is placed in the pipe 3| and is connected by a rod 35 with the handle |4 of the reverse gear shift.

A camshaft 36 is rotatively supported in a bracket 31 mounted on the sides of the housing l. This'shaft has three cams 38, 38 and 38" spaced apart and adapted to press down selector pins or pivots 39, 39 and 39", slidably supported in a guiding bar 40 of the bracket 31. Springs 4| tend to keep the pins in araised position. When depressed the pins slide into holes 42, 42 A gear 43 is mounted on the shaft 36 and is in mesh with a gear sector 44 rotatively mounted on a shaft 45 supported in a bracket 46. The other end of the sector arm 41 has a fork 48 engaging a slot 49 on a hub 50 sliding on a vertical shaft 5| of a governor 52. The governor shaft turns on a foot bearing 53 and has a worm 54 on its upper end in mesh with a worm gear 55 mounted on a driven shaft 56 of the transmission. The springs 51 of the governor are pivotally`supported on an upper hub 58 which is attached to the shaft 5|. The upper ends of the springs flare out under the upper plate 59 of a bell 10. A helical spring 60 is placed between the plate 59 and a sliding bushing 6 l A forked end of a lever 62 presses Iagainst the bushing 6|. The other end of the lever 62 is connected by a rod-63 with a lever 64 connected in turn by a link 65 with an accelerator pedal I 0. The latter is connected with a carburetor throttle valve 220 by a rod 22|. The lever 64 is mounted on a pin 66, and the lever 62 on a pin 61.. The hub 58 and the plate 59 turn with the shaft 5|, the hub being fastened with a pin 68, and the plate sliding on a key 69. The bell 10 is a protective housing for the governor balls 52 preventing their excessive outward movement at high speeds.

Thel shaft 5| has three notches, 1|, 12 and 13, corresponding to the first, second and third speeds, the range of the second speed being between the second and third notches, and for the rst speedbetween the first and second. The hub 50 has a transverse hole inwhich a pin 14 slides being pressed against the shaft by a spring 15.

A cylinder 88 is connected by a pipe 81 with the engine intake manifold 32. A piston 9| is fitted in the cylinder 88 and is connected by a rod 92 with an outside lever 93 connected by a rod 94 with an inside lever 95 engaging a sleeve on a clutch plate 91 of the engine flywheel 98. vThe atmospheric pressure on the piston 9| disengages the clutch when there is vacuum in the pipe 81, the left side of the cylinder 88 being provided with an atmospheric port 88. A valve housing 86 is placed in the pipe 81 and has a sliding valve |08. The latter is provided with a bleeder slot 96 for admitting air into the cylinder when the valve is closed. It also has a lug |65 and -a retrieving spring I I which tends to keep the valve open. A second spring resting against an enlargement |66 limits the movement of the valve. A spring |61 provides a resilient connection between the accelerator pedal and the lug |65 of the valve. 'I'he upper end of this spring rests against a knob or enlargement |61. The valve |08 has an extension 99 connected byl a rod I 08 with a supplementary throttle valve |69 leading from the carburetor (not shown) to the manifold 32. This valve is opened when the valve |08 is opened.` A lever `|00 mounted on a pin |0| engages the lower end of this extension 99 when rotating on the pin under action of a spring |13. The other end of the lever |00 is connected with a rod |02 slidably connected with va rod |02. A spring 202 tends to keep these rods apart thereby deflecting the lever |00V to the right against the tension of the spring |13. The rod |02' is connected with a lever |10 pivoted on a pin |1| and engaging a triple cam |12 on the shaft 36. The projections on the cam |12 are located midway between the corresponding cams 38 and 38. A hook 203 resting on a pivot 204 and turning under action of a spring 205 engages a shoulder 206 thereby preventing the rod |02 from moving to the right. A cord 201 connected with the rod |48 releases the rod |02 when the' valve |46 is opened. The pipes 3|'and 81 merge together into a common pipe I2 provided with a cock |3 which can be closed by hand if it is desired to disconnect the automatic features of the transmission and to operate it manually.

vA transmission interlock is provided in order to prevent the reversefrom being engaged whenv the second or third'gears are in mesh. For this purpose a lever ||4 is provided pivoted on a pin ||5 and having a slot ||6 adapted to engage the loperating end of the reverse gear shift lever The lever |4 is connected by a link |1 with the end of an interlock lever I8 pivoted on a-pin ||9 between the rods 3 and 4. The other end of the rod ||8 has a slot engaging a pin |20 on one end of the rod 4 which operates gears for the second and third speeds. As shown in Fig. 6, any displacement of the rod 4 from its neutral position will cause a pull on the link I|1 closing the lever ||4 over the gear shift lever thereby locking the latter.

A supplementary valve |46 is placed in the pipe 3| and is connected by an arm |41 and a rod |48 with a lever |03 extending from the arm 41 of sector. The other end of the lever |03 fits under the bushing 50 of the governor in its low position corresponding to a certain minimum speed, turns the lever |03 thereby opening the valve |46. A spring |54 tends to keep the valve closed. An arm |52 extends from the valve |46 slidably engaging the lrod |09. A spring |53 opens the valve |46 when the accelerator pedal is depressed.

The pinion 43 turns freely on the shaft 36 and l. is connected by a spring |04 with a cam |12 which also turns on theshaft 36 and is connected by a spring |06 with the cam 38 (Fig. l5) these springs tending to keep the points of the cam |12 in line with the cams 38, 38 and 38".

An arm |50 is pivoted at one end to the housing and has lugs |2| forming a fork engaging the cam |12 with suicient clearance so as to permit the rocking of the cam between the lugs |2| while one of the cams 38, 38 and 38"'retains its contact with the corresponding pin 39. The arm |50 is pressed down by a spring |22 and is prevented from a further movement down by a link |23 connected with one arm of a crank lever |94' (Fig. 13) resting against a lug on the side of the cylinder 26. An arm |25 is pivoted at one end to the side of the housing the other end being pivoted to the rod 24. A spring plate or pawl |26 is attached to one side of the arm 25 so that it becomes deected when passing over a lug- |21 on the under side of the arm |50, but is prevented from being deflected by the side of the arm |25 when the latter moves from the right to the left, thereby raising the arm |50 and releasing the caml |12.

The rod 92 has a lug |18 connected with a rod |19 guided by a bearing |80. A bushing |8| is fastened on the rod |19 and another bushing |82 slides on the rod. A spring 88 is placed on the lrod and is fastened with its ends to the bushings stops |88. A spring |81 tends to keep the valve turned to the left into a position in which the right end of the cylinder 28 is connected with the l Avacuum pipe 8|.

The valve is further retained in this position b a hook |88 pivoted on a pin |89 and provided with a roller |90 vin themiddle. A spring |9| presses the hook down. Its-downward movement is limited by a stop |92. Theroller is placed at such distance from the 'rod |18 that the bushing |82 freely passes under the roller while the larger bushing |8| engages the roller and releases the hook from the arm |84. The bushing |82 has a depending lug |82' which engages alug |98 on the valve thereby turning it oneiquarter of a turn until the bushing |82 passes over the lug |93. This happens because the lug |98 is displaced to the right as shown in Fig. 13. 'I'he lug |98 and the arms |84 and |80 are connected with the inner rotating core of the valve, the outer shell being stationary and connected with the pipes 28 and 8|. The valve is retained in its new posi- -tion byl the end of a lever- |94 engaging the arm |80 shown with dotted lines in 'its new position. A spring |95 tends to turn the lever |94 to the right after it has been deflected by the arm |86. 'I'he other end of the lever |94 rests against the lower end of the rod so that the latter, when lowered, turns the lever |84 thereby releasing thearm' |85 and permitting the valve to be turned to the left by the spring |81.

A rod |91 is pivoted on a pivot |98 and has a lug |98 pressed against the extension 89 by a large to keep the valve open in its raised position.

The lower end of the arm |91` may lbe engaged by a spring or resilient lug 2|0 supported on a rod 20| attached with one end to the rod 24 and sliding at the other end vina bearing 2|2. i

The operation of my transmission is as follows.

With the engine standing still (not running). the rst or lowegear is in mesh, the pin 89 engagingI the bar 2|. The reverse gear shift handle is held by the latch i5' engaging the notch 8'. There being no vacuum in the engine manifold, the clutch will be engaged although the valve |08 is open. The automobile being in low gear will have the same effect as if the brakes were a'ppliedfso that it will not be necessary to use theemergency brake under ordinary parking conditions. I order to start the engine the clutch pedal is depressed releasing the clutch while the starter is placed in operation. For this purpose the starter switch may be connected with the clutch pedal as described in my application serial further operation of the automobile as long as the engine is running., I 'Ihe reverse gear can be used only when the transmission. is in' low gear due to the transmissio'n interlock shown in Figs. 5 and 6. If it is desired to use the reverse, the handle |4 is pulled out, it being released for movement when the vhandle is squeezed by the operators hand thereby turning the-lever 2|4.` The spring latch i5' will be pushed out by thepull on the handle I4.

During the first portion of its movement the rod 85 will slide freely through the hole in the lever I8 so that the latter will not move until the into the pipe 8| thereby admitting air to both sides of the piston 25. The rod 24 can be then moved freely. With the further pull on the handle |4 the gears will pass the neutral point at the notch 4 and then will go into the reverse at the notch 5. The automatic gear shiftywill remain inoperative as long as the reverse is used. This is necessary in order .to prevent any gear shifting operations from taking place if the speed on the reverse reaches a high point. The clutch will remain engaged as-long as the accelerator pedal is depressed which action closes the valve |08, but will be again disengaged as soon as the accelerator pedal is released.

The governor bushing 50 in its lowest position engages the ends of the fork 48 and arm 41. The

bushing .is held in this position by the pin 14 engaging the notch 1|.,l The pull on the rod |48 bythe lever or lug |08 opens the valve |48 against the tension of the spring |54.

When the engine is running, the low gear remains in mesh, and the car will move forward as soon as the accelerator pedal is depressed thereby closing the clutch valve |08. As the speed of the car increases, the governor weights w'ill tend to raise the bushing 50,' but will be held by the pin 14 until the speed reaches a value corresponding to the limiting speed at which the second speed is used. At that speed the bushing |50 will be forced `outof the engagement with the slot 1|` and will jump to the next slot 12 where it will be held. The spring |04 will be wound and placed under tension, but the cam 88. 88' and 88" will remain in contact with the pin 39. as the cam |12 will be held by the lug |2| on the arm |50.` The points of the cam |12 being narrow, the corresponding point will slide off the end of the lever |10, which accordingly will become free to turn to the lright underpressure from the spring |18. this pressure being transmitted through the rods |02 and |02' yand the spring 202. The leverA |00. passing under the end of thebar 89. will raise the same until the notch 209' comes in opposition to the lug |98, which will accordingly engage the notch, holdingthe valve in the open position regardless of the pressure from the accelerator pedal, as the passage of the valve |08 is sulciently large to keep the pipe'81 open in these positions. The pipe 81 will benow open, so that the piston 9| will moveto the right releasing the engine clutch. The movement of the rod 92 will bring the pivoted block |82' against the lug |98 of the valve 29, not moving the latter. however, the arm |84 being held by vthe hook |88. The spring |88 will be compressed vuntil the block |8| raises the roller |90 releasing the hook |88. At the end of the travel of the piston 9|, therefore, when the engine clutch is fully released, the valve 29 will snap through a.

quarter of a turn under 'pressure from the .spring |88 which is much strongenthan the spring |81,

the lug |85 coming to rest against the post |86, deflecting in its movementl the lever |94 and passing above its end. The arm of the hook |88 will.

come to rest against the support |92. In this position of the valve the block |82 will slide over the lug |93. The left side of the cylinder 26 Will be now connected with the vacuum pipe 3| and the right side with the outside air, so that the piston 25 will move to the left bringing the gears into neutral (Fig. 8). The gears cannot move into the reverse from this position as the reverse handle I4 is locked by a latch 2|3 connected with a handle 2|4 pivoted in the handle |4 and kept in' a locked position by .a spring 2 5. It becomes released only when the handle I4 is taken by the operator for pulling the handle out and connecting the reverse gear, the handle 2|4 being then pressed against the handle |4.

Upon completion of the movement of the piston 25 to the left when the gears are brought into the neutral position, the latch spring |26 raises the arm |50 thereby releasing the cam |12. The cams will turn to the position corresponding to the notch 12 of the governor, making one third 'of a turn, and the next lug of the cam |12 will be caught by the returning arm |50 with its lugs |2I. The upward movement of the rod |23 will turn the lever |24 thereby releasing the valve 29, which will return to its original position by making quarter of a turn to the left. The arm |84 will be caught under the hook |88. The valve |08 will remain open all this time as the spring 2| 0 deiiects while passing to the other side of the arm |91. the piston 25 will move to the right, shiftingthe second gear into mesh as per Fig. 9. The speed of the movement of the piston 25 can be adjusted by turning the throttle valves 2|6 in the pipes 28. Upon completion of the movement of the piston 25 the spring 2|0 will engage the arm |91 releasing the extension 99 from the lug |96 and permitting the valve |08 to be moved down and closed by the pressure from the accelerator. The engine clutch will be therefore engaged by the pressure from the clutch spring. Prior to the release of the rod 99 the next lug of the cam |12 will pass under the lever |10 turning the lever |00 to the right. In this position of the mechanism the car will continue to travel on the seconly when the selector barsv 2| and 22 are aligned for the neutral position.

The car will continue to travel on the high gear with the governor locked on the notch 13. It`

will be prevented from any further movement upward by the bell 10 holding the weights 5 2.

Whenever the accelerator pedal is released, the valve |08 will returnk into its open position under action of the springlBT, the notch209 not reaching, however, the lug |96. `The vacuum pipe 81 being open into the cylinder 88, the engine clutch will be released, and the car will coast with the engine disconnected from the transmission. The valve |46 being closed, the hook 2|1 (Fig. I3) will be pulled up bythe rod |48, engaging the end of the arm |85 and -ack- With the valve 29 in the left position,-

ing the valve 29 in the operative position for the gears in mesh. The movement of the piston 9| to the right, therefore, cannot turn the'valve 29, the block IST-'resting against the lug |93, and the spring |83 being compressed. The raising of the arm |88 by the block lI8| will not change the conditions as long as the hook-2|1engages the arm |85. The gears can be shifted, however, if desired, from the third to the second gear, when the car speed is approximately correct for such shift, lby depressing the accelerator pedal for a short time. This action will release the valve 29 from the hook 2 |'I. The governor bushing 50, being pushed down by the springs 51,`will turn the arm 41 with the gear sector 44, turning thereby the cam |12, thus beginning the series of gear shifting operations as described above, except that the pin 39 will take place of the pin 39". With the further slowing down of the car and with the accelerator depressed (for instance, when climbing a hill), the gears will be again changed, from the third to the second, when the car speed reaches a predetermined value.

If the car is coasting with the accelerator pedal released then the valve |08 is open thereby keeping the clutch released. The valve |46 is closed by the spring |54 thereby rendering the motor (cylinder). 26 inoperative. The hook 203 holds the rod |02 preventing the arm |00 from moving even when the lever |10 'becomes released. The hook 2I1 holds the valve 29 preventing its movement even when the piston 9| moves.

The speeds at which the governor changes the gears varies for diiferent accelerator positions. This is accomplished by changing the tension of the springs 51 by means of a lever 62 pressing on the curved ends of the springs 51, the lever 62 being turned by the lever 64 through the rod 63, the lever 64 being connected with the accelerator pedal IIO by a link 65. With this ar- 'rangement greater speeds are required for changing gears from lower to higher when greater engine power is used.

The automatic transmission may be rendered inoperative by closing the cock I3. The handle 8 can be then inserted in the ball of the shifting lever 6 for manual gear shifting. The handle 8 can be also used for engaging the reverse gear, in which case the handle 2|4 must be tied to the handle I4.

My system has the following important advantages:

1. The driver does not use his hands for shifting gears, except for the reverse. Iv-Ie `uses only the brake and accelerator pedals, all the gear shifting being performed automatically at proper speeds. Only one foot is used, either for depressing the accelerator, or for the brake pedal (or starter).

2. The superfluous pedals and handles can be removed from the drivers side thereby leaving the space clear for more passengers.

3. The engine clutch is automatically released when the accelerator pedal is released, thereby be used for releasing the foot brake while the right foot depresses the accelerator.

I claim as my invention:

l. In an automatic transmission for an automobile, the combination with a housing containing transmission gears adapted to ybe connected for different gear ratios, of sliding members for shifting said gears, a reversible motor, a centrifugal governor operatively connected with the driven shaft of said transmission, means to control'the operation of said motor by said governor, connections between said motor and said sliding members, levers included in said connections, removable pivots for said levers, and means to operate said pivots by saidv governor thereby connecting different gear shifts with said motor, 'said motor being adapted to connect said gears when moving in one direction and to disengage said gears when moving in the otherdirection:

2. In an automatic transmission for an automobile, the 'combination with a housing containing transmission gears adapted to be selectively connected for different gear ratios, of sliding members for shifting said gears, each of said members being adapted to shift different gears depending on the direction of its movement, a reversible motor, a centrifugal governor operatively connected with the driven shaft of said transmission, means to control the operation of said motor by said governor, operative connections between said motor and said sliding members, means to selectively change said connections so as to connect different sliding members with said motor andto obtain different directions of' movement of said members` for the -same direction of movement of said motor, one

direction of movement of the. motor being for engaging said gears and the other direction being for disengaging the gears, land means to control-said change of' connections by saidgovernor.

3. In an automatic transmission for an automobile, the combination with a housing contain-l ing transmission gears, of sliding rods in said housing for shifting said gears for different gear ratios, levers operatively connected with said rods, a motor connected with said levers said levers being provided with variable pivoting points, a centrifugal governor operatively connected with the driven shaft of said transmission, means operated by said governor for selective changing of said pivoting points thereby changing the operative connections between said motor and said gears through said rods, vmeans to control said motor by said governor, and means for manual shifting of the reverse gear of'said transmission.

4. yIn an automatic transmission for an automobile, ,the combination with a housing containing transmission gears, of sliding rods in said housing for shifting said gears for different gear ratios, a motor, levers connecting said motor with said rods, said levers being provided with variable pivoting points, means to selectively change said pivoting points for changing the operative connections of said motor with said gears through said rods, and means to control said change of pivoting points and the operation. of said motor by the rotational velocity of the driven' shaft of said transmission.

5. In an automatic transmissionfor an automobile, the combination with a housing containing transmission gears adapted to be connected for different gear ratios, of sliding members fo'r shifting said gears, a reversible motor, va centrifugal governor operatively connected with the driven shaft of said transmision, means to control the operation of said motor-by said governor, connections between said motor Iand said sliding members, levers included in` said. connections, removable pivots for said levers, a cam shaft adapted to operate said pivots, means to operate said cam shaft by said governor thereby changing pivoting points of said levers, said levers being adapted to connect different gear shifts with `said motor for said different pivoting points, and

means to disconnect said transmission from the engine of said automobile 'when said gears are being shifted. 1

6. An automatic transmission for an automobile, in combination a housing containing transmissionfgears adapted to be selectively cona nected for different gear ratios, a motor, a centrifugal governor operatively connected with the driven shaft of said transmission, levers operatively connecting said motor with .said gears, means to change the arrangementof said levers by said governor for different gear ratios, means to control the operation of said motor by Vsaid governor, and means to bring said gears into the neutral position by said motor for each change of said lever arrangements by said governor.

7. An automatic vtransmission for an automobile having a housing containing transmission gears adapted to be connected for different gear. ratios, sliding members for shifting said gears and a driven shaft extended from said transmission, a motor, a centrifugal governor operatively connected with said` driven shaft, levers lopera- -tively connecting said motor with said sliding 

